Unmanned rotary-wing vehicular systems have found increasing use in carrying payloads and serving as the eyes and ears of human operators, having great advantage in not requiring runways for takeoff and landing. Further improvements are needed in unmanned systems for tasks such as precision delivery of sensors, payloads such as ammunition and medical supplies, humanitarian supplies for rescue missions, and critical replacement parts to remote or difficult to reach locations. Ideally the systems also may be used to deploy or deliver sensors for military and industrial surveillance applications and to land on fixed or moving targets without the need for a runway or extensive operator training. Preferably the systems are scalable, so that a compact and portable version for hand operation or cluster deployment and a larger vehicle for resupply may be developed on a common platform.
Related art includes U.S. Pat. No. 7,789,341 (the ‘341 disclosure) and U.S. Pat. No. 8,469,307 (the ‘307 disclosure) to Arlton, which describes a rotor means mounted on an elongate body in which the rotor system blades are collectively and cyclically pitchable with planetary gears, i.e., having a complex hub constructed in the manner of a miniature helicopter. Also relevant are US Pat. Publ. Nos. 2005/0051677 (the ‘677 disclosure) and 2008/0245924 (the ‘924 disclosure) to Arlton. FIG. 22 of the ‘677 disclosure shows an optional tail rotor model having an obvious resemblance to a helicopter.
Commercially, Kamov KA helicopters illustrate twin coaxial counter-rotating rotor flight. The rotor pitch is controlled by a collective and cyclical pitch mechanism actuated by a swash plate. Miniature helicopters are also known, as depicted in U.S. Pat. No. 7,662,013 (the ‘013 disclosure) to Van de Rostyne. Pitch is controlled cyclically using a control ring associated with the main rotor and an actuator. Also shown is a tail rotor for stabilizing flight. However, the miniature vehicles have essentially no payload delivery capability.
U.S. Pat. No. 6,347,764 (the ‘764 disclosure) to Brandon teaches a cylindrical hand-held miniature helicraft having two motor-driven, counter-rotating rotors with collective and cyclic pitch to steer in combination with a deployable tail rotor. The rotors are foldable via hinges into the body for artillery launch. Cyclic pitch control adds substantial complexity and is expensive to produce.
U.S. Pat. No. 8,146,854 (the ‘854 disclosure) describes counter-rotating rotors and a fuselage that maneuvers by adjusting the pitch of the rotor blades through at least 120 degrees, eliminating the need for a tail rotor. However, the device requires at least one on-board gyroscope and extensive programming to operate and has essentially no payload capacity.
Petrides in U.S. Pat. No. 3,149,803 (the ‘803 disclosure) describes a tethered hovering platform with counter-rotating rotary wings having a tilt blade mechanism on a fixed shaft. This is associated with significant loads on delicate pins, limiting its reliability. Directional flight is lacking, requiring a tether system to reposition the platform.
Thus these devices have limitations in capabilities and remain expensive and complex to operate and maintain. There has been a long-standing need for improvements in an unmanned aerial vehicular system that overcome the known difficulties in the art and offers advantages in reliability, portability, and simplicity in use.